Sterilizer for hypodermic syringes



Oct. 29, 1940. w. E. FURR STERILIZER FOR fiYPODERMIC SYRINGES Filed March 15, 1938 2 Sheets-Sheet l Oct. 29, 1940. w. E. FURR STERILIZER FOR HYPODERMIC SYRINGES Filed March 15. 1958 2 Sheets-Sheet 2 Patented Oct. 29, 1940 UNITED STATES PATENT OFFICE STERILIZER FOR HYPODERMIC SYRINGES Walter E. Furr, Franklin, N. C. Application March 15, 1938, Serial No. 196,044

2 Claims.

This invention aims to provide a simple and effective device suitable for ofllce use by physicians and dentists that will insure perfect sterilization of the common types of hypodermic syringes for administering anaesthetics and antitoxins in cartridges.

This invention finds practical application in a flask type of apparatus for sterilizing hypodermic syringes permitting full visibility of the syringe and the sterilizing process, particularly useful to the dental profession. The construction is such as to ensure a quick boiling of the sterilizing medium, which rapidly increases in activity, indicated by bubbling, splashing, surging action on u the suspended syringe in the sterilizing flask. So thoroughly does the action cleanse the syringe that the psychological effect on the mind of the patient immediately it is noted, has a pronounced and beneficial effect on the patients reaction to the treatment.

The purpose of the invention is to give the medical and dental profession a simple and practical sterilizer. To this end one of the objects is to provide a convenient glass tube container to be partly filled with a holding solution, which maintains the sterility of the hypodermic syringe after it has been sterilized and protects the needle point and keeps it sharp and in the finest condition.

Another object is to hold the syringe in a perpendicular position with the needle end suspended in the sterilizing medium during the proces of sterilization, whereby circulation of the vaporized sterilizing medium through the needle is produced and the interior is effectively cleansed and sterilized.

Another object is to provide means for automatically connecting the heatingelement with the electric power supply when a syringe is placed in position in the sterilizing flask, and for breaking the power circuit when the syringe is removed.

All of the containers and exposed parts of the apparatus may be easily cleaned and maintained in sterile condition, and the flask and glass holders are stock articles' readily procurable at medical and dental supply stores in case replacement is necessary for any reason.

With these and other objects in view, the invention consists in the shape and arrangement of the flask and associated parts of the apparatus, and construction features, as hereinafter described and claimed, the proportions, dimensions and arrangement of the parts being selected to suit special requirements as desired.

In the illustrative form of the invention shown in the accompanying drawings:

Fig. 1 is a side elevation of a simple form of the invention having one sterilizing flask and two tubes for holding sterilized hypodermic syringes 5 ready for use, the drawing being partly in crosssection on the line I-| in Fig. 2;

F1Figl. 2 is a plan view of the device shown in Fig. 3 is a side elevation of a preferred form of the invention provided with automatic circuit controlling devices, the drawing being partly in cross-section on the line 33 in Fig. 4; and

Fig. 4 is a plan view of the form of device i1- lustrated in Fig. 3.

Referring to the drawings, the sterilizing flask H is preferably made of Pyrex or other transparent and heat conducting material, and is shaped with a flat or curved bottom H of substantial size and a small neck I3, supported upon an electric heating element Id of conventional type mounted in a suitable base [5 and steadied at its neck by a frame member i 6 also connected to the base. In the device illustrated the frame member has an opening ll somewhat larger than the outer diameter of the flask at its mouth end, so the latter may be inserted through it from below when partly filled with the sterilizing fluid.

In the device illustrated the flask is of 250 cc. capacity, about flve inches high and rests on a three inch circular clay plate having a helical heating element with a power consumption of 550 watts. The flask may be provided with a handle for convenience in removing and replacing it if desired. It is marked with a line l8 (see Fig. 3) to indicate the proper level of the sterilizing medium, and the medium should be maintained at about this level for the best results.

In the form of device illustrated in Figs. 3 and 4, a syringe supporting ring I9 is positioned immediately above and surrounding the opening IT. This ring 19 is of substantially the size of the mouth portion of the flask so that it rests upon the latter in the normal operating position of the apparatus, and in the inoperative position this ring is supported above the mouth of the flask by a lever 20 which is pivoted at a point 2| between its ends to the frame It at one side of the apparatus, and which is held in its raised position by a link 22 extending from its free end 23 to the electrical contact device 24 in the base. A weight or spring 25 maintains the lever arm with its ring end up ready to receive the syringe 26 when the apparatus is not in use, and in this potact device. When the syringe is placed in the flask as illustrated in 'Fig. 3, the arm is depressed and the contact elements 21, 28 are brought together to complete the circuit.

Any suitable form of contact device may be utilized in this arrangement, and connected to the supply circuit and heating element in acco'rdance-with established practice, these details being no part of my invention.

In both forms of device illustrated, the base is open at the bottom and provided with openings or ventilators 29 to permit circulation 'of air through the apparatus to aid in the rapid heating of the flask and to cool the metal parts of the apparatus adjacent to the heating element and prevent overheating of the base while the apparatus is in use. switch 30 is advantageously provided for manual control of the heating current.

Upon each side of the flask are mounted one or more glass containers 3|, similar in size and shape to ordinary laboratory test tubes, to receive the sterilized syringes and protect them from contamination and injury when out of use. These containers may be filled with 70% alcohol solution or other antiseptic holding medium.

Preferably sockets or depressions 32 are provided in the top of the base to receive the bottom ends of these containers, the top ends being guided by suitable openings in the frame member I6. The open ends of these containers 3|, respectively fit snugly around and support the collar portion of the syringe immediately below the handle so as to suspend it in full view while awaiting use, thus enabling the practitioner to know its condition at all times, a matter of considerable practical convenience in the administering of repeated injections from the same ampule or hypodermic charge.

In the usual operation of the apparatus illustrated in Figs. 3 and 4, the hypodermic syringe 26 is placed iri the flask l I with its needle 33 submerged in the sterilizing medium, preferably water, the weight of the syringe being sufiicient to depress the arm 20 and complete the electrical circuit through the heater element. The weight of the syringe is supported by the neck of the flask thus relieving the contact members from the strain of supporting this weight, and from shock when the syringe is placed in the flask; An adjustment 34 is provided, in the link 22 in order to insure proper contact between the members 21, 28 without imposing too great a strain upon them.

In both types of apparatus the shape and size of the flask are such as to provide a comparatively large bottom area exposed to the heater and a considerable volume of space above the liquid for receiving the vapor as produced, with a substantial area of the side walls and neck in the vapor space upon which some of the vapor will condense and run back into the flask, the uncondensed part of the vapor passing out of the flask through the narrow space in the neck surrounding the syringe so as to sterilize the handle portion and avoid the creation of excessive pressure in the flask. Little, if any, liquid will be carried out of the flask with the vapor even when boiling vigorously if the size and proportions of the parts are suitably chosen.

An important advantage in this method of A separate toggle orsnap sterilizing hypodermic syringes is the quick, rapid boiling of the sterilizing medium which soon fllls the flask above the level of the sterilizing medium with steam or vapor. This heated vapor flows at intervals down through the canal of the needle 83, as is evidenced by intermittent bubbling at the point of the needle, which thoroughly washes out any saliva, mucus, bacteria or novocaine salts, and hence completes the sterilization of the syringe needle internally and externally from end to end. 1 -It is apparent from the foregoing description that all of the operations are visible to both doctor and patient, and the condition of the apparatus and instruments readily apparent at all times. The cleanliness of all parts of the apparatus concerned in maintaining sterile conditions and protecting the syringes and needle points can be ascertained and maintained with ease, and only ordinary attention is required to ensure complete sterility of the needle point and interior canal at all times prior to use.

Should the practitioner leave the apparatus witha syringe in the flask and the current-on for any length of time such that all the liquid boils away, the air cooling provided will prevent damage to the apparatus. Moreover, the fact that the current is left on is immediately evident to anyone present by observation as the rapidly boiling flask attracts the attention.

The device may be used effectively without the automatic current control, and the invention contemplates omitting of the automatic switch and operation by means of a manual switch under the control of the practitioner. or oiflce attendant as illustrated in Figs. 1 and 2.

, Having described a preferred form of my invention, what I claim is as follows:

1. A sterilizing apparatus having an electric heating element providing a support for a flask, a transparent flask positioned thereon, said heating element being mounted in a base provided .wi'tha frame extending upwardly to approximately the height of the neck of the flask, means carried by said frame for loosely encircling the neck of the flask to position the latter on the heating element, means for supporting a syringe point down in said neck, said syringe supporting means being mounted on said frame for limited vertical movement, and means actuated by movement of said syringe supporting means for closing the electric circuit supplying said heating element.

2. An apparatus of the class described including a flask, a syringe holding ring positioned over and spaced above the mouth of said flask, a heating element upon which [the flask rests, a switch including a movable contact member for controlling the current supply to said heating element, a pivoted support for the syringe holding ring and spring means for sustaining it, and an adjustable connection between said support and said contact member whereby the weight of the syringe presses the holding ring down and in contact with themouth of the flask and moves said contact member to close said switch, thus turning the current on the heating element, the removal of the syringe permitting the holding ring to be lifted upwards by said spring means to release the switch contact, thereby breaking the electrical connection to the heating element.

WALTER E. FURR. 

